// For flags

CVE-2024-36478

null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'

Writing 'power' and 'submit_queues' concurrently will trigger kernel
panic:

Test script:

modprobe null_blk nr_devices=0
mkdir -p /sys/kernel/config/nullb/nullb0
while true; do echo 1 > submit_queues; echo 4 > submit_queues; done &
while true; do echo 1 > power; echo 0 > power; done

Test result:

BUG: kernel NULL pointer dereference, address: 0000000000000148
Oops: 0000 [#1] PREEMPT SMP
RIP: 0010:__lock_acquire+0x41d/0x28f0
Call Trace:
<TASK>
lock_acquire+0x121/0x450
down_write+0x5f/0x1d0
simple_recursive_removal+0x12f/0x5c0
blk_mq_debugfs_unregister_hctxs+0x7c/0x100
blk_mq_update_nr_hw_queues+0x4a3/0x720
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_submit_queues_store+0x79/0xf0 [null_blk]
configfs_write_iter+0x119/0x1e0
vfs_write+0x326/0x730
ksys_write+0x74/0x150

This is because del_gendisk() can concurrent with
blk_mq_update_nr_hw_queues():

nullb_device_power_store nullb_apply_submit_queues
null_del_dev
del_gendisk
nullb_update_nr_hw_queues
if (!dev->nullb)
// still set while gendisk is deleted
return 0
blk_mq_update_nr_hw_queues
dev->nullb = NULL

Fix this problem by resuing the global mutex to protect
nullb_device_power_store() and nullb_update_nr_hw_queues() from configfs.

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-06-21 CVE Reserved
  • 2024-06-21 CVE Published
  • 2024-10-11 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.5 < 6.1.119
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 6.1.119"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.5 < 6.6.55
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 6.6.55"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.5 < 6.9.4
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 6.9.4"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.5 < 6.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5 < 6.10"
en
Affected